Isobutyryl group

Polyethylenimine with 10% of residues acylated by butyryl (O) or isobutyryl ( ) groups. 

Figure 3.2 Extent of binding of methyl orange at pH 7.0 and 25 °C as a function of free (nonbound) dye concentration. (1) Polyethylenimine (PEI) with 8.4% of residues acylated by lauroyl groups. (2) PEI with 11.5% of residues acylated by hexanoyl groups. (3) PEI with 10% of residues acylated by butyryl or isobutyryl groups. (4) PEI-600. (5) Bovine serum albumin.

New amino acid-tetrahydropterin conjugates were synthesized from A2-isobutyryl-6,7-dimethyl-5,6,7,8-tetrahydropterin (169) by either direct acylation (170) or via a succinate linker (171) followed by removal of protecting groups and ammonia treatment to deblock selectively the isobutyryl group (Scheme 26) <89MI 718-08). 

Protection of the 3 -hydroxyl group in stepwise synthesis of oligo(deoxyribonucleotides) has usually involved the acetyl or, sometimes, the isobutyryl group, with removal after each condensation by brief treatment with base (so as not to remove alkali-labile, N-acyl pro-... 

Note Reactions were run and worked up as described in Table II, footnote. Product analysis was by integration of H-NMR signals for the methyl protons in the isobutyryl group of benzoic isobutyric anhydride (8 (CDCb) 1.30, d) and isobutyric anhydride (8 (CDCI3) 1.24, d). 

Nucleoside phosphoramidites or methylphosphonamidites with protecting groups on the bases that are removed faster or milder than the conventional benzoyl and isobutyryl groups have been developed, and several are commercially available. Papers in this area include one on the preparation and use of dialkylformamidine protected dA and dG phosphoramidites, which together with dC yielded oligonucleotides that were completely deprotected by cone, aqueous ammonia in 1 h at 65... 

To overcome the dilemma either of crystalline or low-viscosity compounds, the mixed esters were produced and investigated. Several of those were found to produce viscous liquids which would not crystallize. From evaluations in combination with various film-forming polymers, sucrose acetate isobutyrate was selected as producing properties most desirable as a coatings modifier (Figure 1). Of course, there are many possible combinations from the various ratios of acetyl to isobutyryl groups. From a study of this factor, it... 

---